Hardware Limited Operating Strategy

Hardware Limited Operation Strategy (HLOS) -- This system of special circuitry provides minimal engine operation should the PCM (mainly the Central Processing Unit or EPROM) stop functioning correctly. All modes of Self-Test are not functional at this time. Electronic hardware is in control of the system while in HLOS.

^ HLOS Allowable Output Functions:
- Spark output controlled directly by the PIP signal.
- Fixed fuel pulse width synchronized with the PIP signal.
- Fuel pump relay energized.
- Idle Speed Control output signal functional.

- HLOS Disabled Outputs To Default State:
- EGR solenoids
- No converter lock-up